Surface emitting laser and optical coherence tomography apparatus including the same

A surface emitting laser comprising:

• a lower reflector;
• an active layer;
• a gap portion;
• an upper reflector;
• and
• a driving unit,
• wherein the lower reflector, the active layer, the gap portion, and the upper reflector are arranged in that order,
• wherein the surface emitting laser is capable of varying a wavelength of emitted light by changing a distance between the upper and lower reflectors,
• wherein the driving unit moves one of the upper and lower reflectors in an optical axis direction of the emitted light, and
• wherein at least one of the upper and lower reflectors includes
• a stacked body in which first layers and second layers are alternately stacked, the second layers having a refractive index lower than a refractive index of the first layers, outermost layers of the stacked body being the first layers, and
• a third layer provided on at least one end of the stacked body and configured such that an optical thickness nd of the third layer satisfies 0<nd<λ0/2, where λ0 is a center wavelength of the emitted light, the third layer having a refractive index that is lower than the refractive index of the first layers and higher than a refractive index of a layer provided adjacent to the third layer at a side opposite to a side at which the stacked body is provided.